Jo Yongjae, Park Hyemi, Lee Seho, Kim Inki
Department of Biophysics, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon 16419, Republic of Korea.
Department of Biophysics, Department of Intelligent Precision Healthcare Convergence, Institute of Quantum Biophysics, Sungkyunkwan University, Suwon 16419, Republic of Korea.
Nanophotonics. 2025 Feb 7;14(8):1171-1183. doi: 10.1515/nanoph-2024-0587. eCollection 2025 Apr.
Hadamard matrices, composed of mutually orthogonal vectors, are widely used in various applications due to their orthogonality. In optical imaging, Hadamard microscopy has been applied to achieve optical sectioning by separating scattering and background noise from desired signals. This method involves sequential illumination using Hadamard patterns and subsequent image processing. However, it typically requires costly light modulation devices, such as digital micromirror devices (DMDs) or spatial light modulators (SLMs), to generate multiple illumination patterns. In this study, we present spectral Hadamard microscopy based on a holographic matasurface. We noticed that certain patterns repeat within other Hadamard patterns under specific condition, allowing the entire set to be reproduced from a single pattern. This finding suggests that generating a single pattern is sufficient to implement Hadamard microscopy. To demonstrate this, we designed a metasurface to generate an illumination pattern and conducted imaging simulations. Results showed that holographic metasurface-based Hadamard microscopy effectively suppressed scattering signals, resulting in clear fluorescent images. Furthermore, we demonstrated that hyperspectral imaging can be achieved with Hadamard microscopy using dispersive optical elements, as the orthogonality of the Hadamard pattern enables to resolve spectral information. The reconstructed hyperspectral images displayed a color distribution closely matching the synthetic hyperspectral images used as ground truth. Our findings suggest that optical sectioning and hyperspectral imaging can be accomplished without light modulation devices, a capability typically unattainable with standard wide-field microscopes. We showed that sophisticated metasurfaces have the potential to replace and enhance conventional optical components, and we anticipate that this study will contribute to advancements in metasurface-based optical microscopy.
由相互正交向量组成的哈达玛矩阵，因其正交性而在各种应用中得到广泛使用。在光学成像中，哈达玛显微镜已被应用于通过将散射和背景噪声与所需信号分离来实现光学切片。该方法涉及使用哈达玛图案进行顺序照明以及随后的图像处理。然而，它通常需要昂贵的光调制设备，如数字微镜器件（DMD）或空间光调制器（SLM），来生成多个照明图案。在本研究中，我们提出了基于全息超表面的光谱哈达玛显微镜。我们注意到在特定条件下，某些图案会在其他哈达玛图案中重复出现，这使得整个图案集可以从单个图案中再现。这一发现表明，生成单个图案就足以实现哈达玛显微镜。为了证明这一点，我们设计了一个超表面来生成照明图案并进行了成像模拟。结果表明，基于全息超表面的哈达玛显微镜有效地抑制了散射信号，从而得到清晰的荧光图像。此外，我们证明了使用色散光学元件，哈达玛显微镜可以实现高光谱成像，因为哈达玛图案的正交性能够解析光谱信息。重建的高光谱图像显示出的颜色分布与用作地面真值的合成高光谱图像紧密匹配。我们的研究结果表明，无需光调制设备即可完成光学切片和高光谱成像，这是标准宽视场显微镜通常无法实现的能力。我们表明，复杂的超表面有潜力替代和增强传统光学元件，并且我们预计这项研究将有助于基于超表面的光学显微镜的发展。
